LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Long-term debt obligations
Long-term debt	$ 145,030	$ 155,985
Less current portion	39,861	43,044
Long-term debt, less current portion	105,169	112,941
Payments under long-term debt obligations
Due in one year or less	42,771
Due after one year through two years	32,802
Due after two years through three years	25,679
Due after three years through four years	18,872
Due after four years through five years	32,306
Due after five years	421
Total payments	152,851
Less amounts representing interest	7,821
Long-term debt	145,030	155,985
Term Loan
Long-term debt obligations
Long-term debt	92,500	95,000
Interest rate (as a percent)	1.70%
Payments under long-term debt obligations
Due in one year or less	13,434
Due after one year through two years	15,796
Due after two years through three years	18,184
Due after three years through four years	18,658
Due after four years through five years	32,085
Total payments	98,157
Less amounts representing interest	5,657
Long-term debt	92,500	95,000
Notes payable
Long-term debt obligations
Long-term debt	34,080	37,756
Weighted-average interest rate (as a percent)	3.00%
Payments under long-term debt obligations
Due in one year or less	16,728
Due after one year through two years	14,227
Due after two years through three years	4,282
Total payments	35,237
Less amounts representing interest	1,157
Long-term debt	34,080	37,756
Capital lease obligations
Long-term debt obligations
Long-term debt	18,450	23,229
Weighted-average interest rate (as a percent)	4.40%
Payments under long-term debt obligations
Due in one year or less	12,609
Due after one year through two years	2,779
Due after two years through three years	3,213
Due after three years through four years	214
Due after four years through five years	221
Due after five years	421
Total payments	19,457
Less amounts representing interest	1,007
Long-term debt	$ 18,450	$ 23,229